In known electro-pneumatic brakes the braking pressure of each bogie, which bogie usually comprises two braked axles and two or more pneumatically actuated brake cylinders for each axle, is monitored using a pressure sensor which is connected downstream of a unitary pressure intensifier (EDU) may be a relay valve. As a result of this arrangement, however, even relatively major leaks in the brake pressure lines under braking pressure are not detected. The cause of this is to be seen in the replenishment output of the unitary pressure intensifier (EDU), which replenishes the brake pressure lines with compressed air in the event of leaks but thereby makes it more difficult to identify a loss of braking pressure. This is problematic since a braking pressure loss cannot be detected reliably. It must also be assumed here that not only the brake cylinder affected by the leak in the associated brake pressure line becomes inoperative but the further coupled brake cylinders of the bogie are at least partially vented via the leak.